Apparatus for electric control systems



June 1932. SORENSEN; I 1,865,150

APPARATUS FOR ELEGTRICI'CONTRIGL svs'rnms Filed March 13, 1951 Egl Filter 84 49 NC 48 NR 55 [V13 40 Amplzfier 71 9 IN VEN TQR."

N Q ATTORNEY.

Patented June 28, 1932 v UNITED STATES PATENT OFFICE ANDREW J. SORENSEN, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE, UNION SWITCH 82; SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA APPARATUS FOR ELECTRIC CONTROL SYSTEMS Application filed March 13, 1931. Serial No. 522,247.

My invention relates to apparatus for electric control systems, and particularly to c0ntrol systems for railway train brakes.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig 1 1s a diagrammatic view of a preferred form of a locomotive carried equipment for a system embodying my invention when applied to the control of an auxiliary brake controlling mechanism located at some other point on the train. Fi 2 is a diagrammatic view of a preferred? rm of the control apparatus for the auxiliary mechanism to be'installed at some point on the train other than the 'locomotive. While the location of this auxiliary mechanism shown in Fig. 2 may be at any point on the train, it will be spoken of in this description as being carried in the caboose 1n order to clarify the description.

Referring to Fig 1, the engineers brake valve B is of the standard type capable of assuming the several brake controlling positions release, running, lap, service and emergency. As shown schematically in the drawing, the contract member 2 is operatively connected to the handle 3 of the brake valve B. The contact member 2 is adapted to engage the arcuate contact 4 in all positions of the valve B and also to engage a series ofcontacts 5, 6, 7 and 8 when the brake valve occupies its release, running, lap and emergency positions respectively.

Located on the locomotive is afgenerator G of alternating carrier current, the frequency of which may for example be five thousand cycles per second. However, it will be understood that my invention is not limited to any definite frequency for the generator G. This generator G may be any convenient type, many of which are well known to the art, among them being the vacuum tube type. As this generator G forms no part of my invention, this source of alternating carrier current is shown in the drawing merely by a symbol in order to simplify the figure. The output of the generator G is at times supplied to the inductors 9 and 10 located in inductive relation with the two traihc rails 1 and 1 respectively.

Also located on the locomotive are four mechanically tuned oscillators M M M and M one associated with each of the positionsrelease, running, lap and emergency, of the brake Valve B. These mechanically tuned oscillators may take different forms but a preferred form is that as shown and described in my copending application for Letters Patent, Serial No. 426,563, filed Feb. 7, 1930. These mechanically tuned oscillators are all substantially alike and a description of one will suiiice for an understand ing of all. Looking at oscillator M it has a field structure F and an armature H pivoted at P which carries contact members 11 and 12. Normally the whole structure is biased to the position as shown in the Fig. 1 in such manner that contact members 11 and 12 are not directly between the poles 13 and 14 of the field F. The field F is provided with a Winding 120 which is included. in a circuit extending from the battery 16 along wire 17, winding 120, wire 18, contact member 12, wire 19, contact 6, contact member 2, arcuate member 4 and wire 20 back to the opposite terminal of the battery 16. The closing of this circuit through the winding 120 energizes the field F and causes armature H to rotate in a counter-clockwise direction. After a certain amount of rotation of armature H, contact member 12 opens removing the energization of the field winding 120. H rotates a little further and then begins to return to its normal position due to the biasing. In due time contact 12 closes again reapplying current to the winding 120 and reversing the direction of rotation of H. The armature H will thus oscillate about P as a center, its period depending upon the mass associated with the armature Hand the characteristics of the biasing arrangement. The contact member 11 normally engages with its righthand contact 21 but breaks contact with 21 and enga es the left-hand contact 22, as armature rotates in the counter-clockwise direction. The contact member 11 will thus make and break contact with the contacts 21 and 22 once for each oscillation of the armature H. As stated above, the four mechanically tuned oscillators are similar except that each is adjusted to a definite predetermined period of oscillation. While my invention is not limited to any particular period of oscillation for these mechanically tuned oscillators, they will be referred to in the description as being eighty, one hundred twenty, one hundred eighty and two hundred seventy cycles per minute for M M M and M respectively. In other words, the armature H of each of the respective oscillators will make a given number of oscillations per minute when the field winding is energized in a manner as described for the oscillator M Attention is called to the fact that in Fig. 1, the reference character given to designate the field winding of each of the respective oscillators is the same as the oscillations per minute of that oscillator.

In the same manner that a circuit is closed to the field winding 120 of M when the brake valve 13 is positioned at the running position, a circuit is completed to the winding 80 of the oscillator l C when the valve handle 3 is placed at the release position and contact member 2 engages the contacts 4 and 5. If the handle 3 is placed at lap position and contact member 2 engages contacts 4 and 7, then the circuit is completed to the field winding 180 of the oscillator M and in like manner when the handle 3 is placed at emergency position so that 2 engages contacts 4 and 8, the circuit is completed to the winding 270 of the oscillator M t is to be noted that no oscillator is provided for the service position of the brake valve. The reason for this will appear later in the description. It follows from the foregoing that each mechanically tuned oscillator is associated with but one position of the brake valve and that one and only one of the oscillators willbe operated at a time.

With the mechanically tuned oscillator M rendered active by the brake valve handle 3 being placed at its running position, the contact member 11 of M alternates between the two contacts 21 and 22. When 11 engages contact 22, it completes the output circuit of the carrier frequency generator which extends from one terminal of generator G along wire 23, contact 22, contact member 11, wire 24, contact 25 of oscillator M contact member 26, wire 27, inductors 10 and 9 and wire 28 back to the other terminal of the generator G. WVhen the contact member 11 of the M oscillator engages 21, it completes the circuit to the input filter of the receiving apparatus on the locomotive to be described later. This input circuit can be traced from the outside terminal of the inductor 10 along wire 27, contact member 26, contact 25, wire 24, contact member 11. contact 21, wire 29, contact member 30 of M wire 31, contact member 32 of M wire 33, the input filter J and wire 34 to the outside terminal of the inductor 9.

From what has been said it is apparent that with the brake valve B in the running position the output of the carrier frequency generator G and the input circuit for the receiving apparatus on the locomotive are connected to the inductors 9 and 10 alternately at Substantially one hundred twenty times per minute. It follows then that as long as M is active, the traffic rails 1 and 1 are supplied with impulses of carrier current one hundred twenty times per minute while once each period of the operation of M, the receiving apparatus on the locomotive is placed in conditionto receive energy from the traffic rails 1 and 1. With the brake valve at release position, and oscillator M rendered active, the impulses of the carrier current supplied to the rails 1 and 1 occur eighty times per minute and the receiving apparatus is placed in condition to receive energy from the rails eighty times per minute. Likewise with the brake valve at lap position, the rails are supplied with impulses of carrier current at the rate of one hundred eighty times per minute and the receiving apparatus connected to the inductors 9 and 10 at the same rate. Again with the brake valve placed at the emergency position the rate of alternately connecting the output of G and the input of J to the inductors 9 and 10, will be two hundred seventy times per minute. In the service position of the brake valve, none of the mechanically tuned oscillators are active and the input circuit is connected to the coils 9 and 10 as will be evident by an inspection of Fig. 1. To sum up thus far, during one half of a cycle of oscillation of M M M or M carrier current is fed to the track rails and during the other half cycle, the locomotive equipment is in a condition to receive incoming current impulses.

Referring to Fig. 2, the apparatus here shown is located at some point on the train other than the locomotive and as previously stated, I shall consider it to be in the caboose. This caboose is provided with a main reservoir MR, a feed valve F and a plurality of electropneumatic valves D adapted to reproduce the functions of the engineers valve on the locomotive. It will be understood, of course, that the caboose is further provided with a compressor, etc., to insure a proper supply of air pressure in the reservoir MR. Valves D D and D are each biased to a closed position and each valve is opened when its associated magnet 35 is energized. The valve D is biased to its open position and is closed when its associated magnet 35 is energized. When the valve D is opened, that is, when its magnet 85 is energized, main reservoir MB- is connected with the brake pipe BP so that the apparatus will then reproduce the condition which exists on the locomotive when the engineers valve is in release position. When the valve D is opened, the brake pipe is connected to the feed valve F" thereby reproducing the condition existing on the comotive when the engineers valve is in the running position. WVhen the valve D is opened, that is, when its magnet is deenergized, the brake pipe connected to the atmosphere through a vent of such characteristics as to produce a reduction in the brake pipe pressure atsubstantially the service rate of the usual brake valve to effect the service application of the brakes. lVhenthe valve D is opened by its magnet 35 being energized, the brake pipe is connected to the atmosphere through a vent of such characteristics as to cause an emergency rate of reduction of brake pipe pressure and an emergency application of the brakes. WVhen the valve D is energized and the remaining valves D D and D all deenergized, both the supply and the exhaust passages to the brake pipe are blanked and the function reproduced by the auxiliary apparatus corresponds to thelap position of the engineers brake valve.

The magnets 35 of the several valves are controlled by the slow releasing relays R R R and R When the relay E is energized, as the result of the engineers valve being placed in the running position as will be fully described later, current is supplied by battery 36 along wire 37, magnet 35 of D front contact of the armature 38 of relay R back contactof the armature 39 of the relay R mag net 35 of valve D and wire it) to the negative terminal of the battery 36. In the event the relay R is energized as it will be when the engineers valve is placed in release position, the circuit from battery 36 will eXtend along wire 37, magnet 35 of D front contact of the armature 39, of relay R magnet 35 of D and back to battery 36 by wire 40. Again when the engineers valve is in lap position, the relay B is energized and the front con tact of its armature ll is closed to complete a circuit from battery 36 along wire 37, re sistance 42, front contact ll of relay R back contact 38 of relay R back contact 39 of relay R magnet 35 of the valve D and to battery 36- by wire 40. Again when the relay R is energized as it will be when the engineers valve is placed in the emergency position, the circuit from the battery 36 includes the magnet 35 of D front contactof the armature 43 of relay R and the magnet 35 of the valve D in series. lVith the magnet 35 of the service valve D thus normally energized when any one of the magnets of the other brake valves are energized, a loss ofcontrol for any reason whatsoever results in a service application of the brakes and insures thereby a closed circuit principle for mysystem. I will now describe the control of the relays R R Pd and R i p 7 The caboose is provided with pick-up coils 4% and 45 located 'in inductive relation with the traflic rails 1 and l respectively. At times these pick-up coils are connected with the input circuit of the input filter J of the receiving apparatus in the caboose. This receiving apparatus includes the input filter J and an amplifier A which may take any of the forms well known to the art and they form no part of my invention, they are indicated only, in the figure, by a symbol. It is deemed sufficient to say that their part in the operation of the apparatus of Fig. 2 is such that when coded impulses of carrier frequency current are applied to the input circuit, impulses of direct current are delivered to the direct current relay d6. vVith relay 46 thus energized it will close the front contact of its armature 47 at each incoming impulse of current and will close the back contact of its armature between incoming code impulses. That is to say, the armature 4-7 of the relay i6 is operated eighty, one hundred twenty, one hunlred eighty or two hundred seventy times per minute depending upon which of the mechanically tuned oscillators of Fig. l is actiy e to code the carrier frequency current supplied by the generator G on the locomotive. In the caboose, there is provided four mechanically tuned oscillators substantially similar in construction to the oscillators on the locomotive and tuned to the same frequencies. Oscillator N is tuned to eighty cycles per minute, oscillator N to one hundred twenty cycles per minute and N and N tuned to one hundred eighty and two hundred, seventy cycles per minute respectively. The energizing coil 80 of the oscillator N is supplied with current from the battery 36 over wire 37, winding 80, contact member 48, wire d9, the front contact of the armature 47 of relay 46 and back to the negative terminal of battery 36. In like manner the energizing coils of each of the other oscillators N N and N are provided with an energizing circuit that includes one of its own contact members and the front contact of the armature 47.

Through the front and back contacts of the armature l7 of relay -16, current is also supplied from the battery 36 to the two halves of the primary winding 50 of a transformer 51. The secondary 52 of transformer 51 is connected to the input terminals of a full wave rectifier 53 while the output terminals of rectifier 53 are connected to the winding of a slow releasing relay 54-. It follows then that with relay 46 operated by any of the incoming code impulses, the relay 5% will be retained energized holding its armature 55 in engagement with its front contact while with the relay 46 ceasing to be operated on code, the relay 54 becomes deenergized.

To explain how the mechanically tuned oscillators in the caboose operate, I shall assume that one hundred twenty cycle code impulses are being picked up by the inductors 44 and 45. These impulses operate the relay 46 at the same rate so that its armature 47 engages its front and back contacts one hundred twenty times per minute. As armature 47 engages its front contact, current from the battery 36 is supplied to the winding 120 of the oscillator N through the contact 56 causing the armature H of N to rotate in the counterclockwise direction and in due time open the contact 56 to rupture the circuit through the winding 120. The armature H of N then rotates towards its former position due to its biasing and by the time 56 closes again, a new code impulse will have been received to operate relay 46 causing its armature 47 to engage its front contact. Thus, by virtue of the fact that N is mechanically tuned to one hundred twenty cycles per minute the same as the rate of code impulses, the code impulses will cause the oscillator N to operate continuously. While the other oscillators are receiving the code impulses, they will not receive enough energization to operate their armatures at full stroke because they are tuned to other frequencies and the result is that their contacts will remain substantially in the position as shown in the Fig. 2. With the oscillator N operated at its full stroke, its contact member 57, which is normally positioned midway between the field poles of N will alternately make contact with its left and right hand contacts one hundred twenty times per minute. Also, the contact member 58 of N will engage its left-hand contact at the same rate. During the time the contact member 58 engages its contact, current is supplied to the slow releasing relav R from the battery 36 along the wires 37 and 84, armature 55 of the relay 54, wire 59. contact member 58, winding of relay R and wire back to the battery 36. As relay 1? is slow-releasing, it remains steadily energized as long as the oscillator N is operated. As previously pointed out, with the armature 38 of the relay R is engagement with its front contact, the magnets of the brake valves D and D are energized. It follows then that as long as one hundred twenty code impulses are received in the caboose to operate the relay 46, the oscillator l" is operated and relav R retained energized and in turn the brake valves D and D are energized causing thereby the auxiliary mechanism to reproduce the running condition of the engineers valve. A similar analysis will show that when the incoming code impulses are at the rate of eighty cycles per minute, the oscillator N is operated and the relay 54 energized, and that with N operated to close the contact member 60, the slow releasing relay R is selected and the brake valves D and D retained energized to set up the release condition of the train brakes.

Also, in the event the incoming impulses are of one hundred eighty cycles per minute, the oscillator N is operated to close its contact 61 resulting in the slow releasing relay B being selected and the brake valve D only energized, reproducing thereby the lap condition of the train brakes. Again when the incoming code impulses are of two hundred seventy cycles per minute, the oscillator N is operated to close its contact 62 with the result that the relav R is selected and the valves D and D energized to reproduce the emergency application condition of the train brakes.

In my invention as here disclosed, I have provided indication apparatus on the locomotive controlled, by the auxiliary brake mechanism in the caboose so that the locomotive driver will know whether or not a condition that he has set up on the locomotive is being duplicated in the caboose. This necessitates the providing of a transmitting apparatus in the caboose and a receiving a paratus on the locomotive. Furthermore, in order to insure that the return indication shall mean not only that the control impulses have reached the caboose but that the appropriate valves have been energized and have functioned, each valve is provided with a multiple contact member which makes on its front contact when the valve is energized and which makes on its back contact when the valve is deenergized. These contacts associated with the various brake valves are included in the output circuit of a generator oi as will shortly appear.

There is installed in the caboose, a generator of carrier frequency current G1. This generator may be and preferably is similar to the generator on the locomotive. The generator G1 and the receiving apparatus in the caboose are alternately connected to the inductors 44 and 45. T 0 illustrate, let us assume the case where one hundred twenty code is received at the caboose. At the very start, the auxiliary mechanism is inactive and the brake valves all deenergized. Under this deenergized condition, the inductors 44 and are connected to the receiving apparatus by a circuit that extends from the outside terminal of the inductor 45 along wire 69, back contact of the contact member 68 of the valve D wire 7 2, input filter J and wire 71 to the outside terminal of the inductor 44. In due time, the one hundred twenty code effects the energization of the valves D and D With valve D energized so as to raise its armature 68 into engagement with its front contact, the receiving circuit traced above is ruptured but, however, the contact member 57 associated with the oscillator N now completes the receiving circuit once each cycle. As the armature H of N rotates away from its normal position, the contact member 57 engages its left-hand contact and in doing so completes the output circuit for the generator G1 which output circuit may be traced from one terminal. of G1 along wire 63, back contact of the armature'64 of the valve D front contact of the armature attached to the movable part of the valve D ,-wire 66, left-hand contact of 57 wire 67, front contact of the armature 68 attached to the movable part of valve D wire 69, inductors 45 and 4a and wire 70 to the opposite terminal of a generator G1. As the armature H of N rotates back to its normal position, the biasing will cause it to'rotate still further thereby bringing the contact member 57 into engagement with its right-hand contact. As 57 engages its right-hand contact, it closes the input circuit by completing a path from the wire 72 through the right-hand contact of wire 67, armature 68, wire 69, inductors L5 and 4d and wire 71 to the other terminal of the input filter J. Thus with 57 oscillating between its two contacts, the transmitting generator G1 and the input circuit to the filter J are alternately connected to the inductors 44 and 45.

Since the contact members 57 and 56 are both actuated by the armature H of N, they both close their right-hand contacts during approximately the same interval of time. It is clear, therefore, that the contact 57 connects the inductors to the receiving apparatus every cycle in time for an energizing impulse to be received while the front contact 47 is closed. Since the receiving period in the caboose substantially coincides with the sending period on the locomotive, the sending period of the former must coincide substantially with the receiving period of the latter. it being recalled that the inductors 9 and 10 on the locomotive are alternately connected to the generator G and the input filter J of the locomotive by the contact member 11 of the oscillator M In the event the code received at the caboose is one of eighty cycles per minute, the oscillator N will become active to actuate its contact 60 to close the energizing circuit for the relay R and in turn, to close the circuit to the magnets of the valves D and D and also to actuate its'contact member 7 3 to alternately connect the generator G1 and input filter J to the inductors 4:4; and 45 at the rate of eighty times per minute. It follows then that oscillator N in the caboose will operate in step with the oscillator M on the locomotive and that the receiving period of the caboose apparatus substantially coincides with the sending period of the 10- comotive apparatus and that the sending period of the caboose coincides with the receiving period on the locomotive. In a like manner when the incoming code at the caboose is one of one hundred eighty cycles per minute, the oscillator N is rendered active to actuate its contact members 61 and 74:. With members 61 engaging its contact, the

slow releasing relay B is energized and the brake valve D in turn energized to reproduce a lap condition of the brakes. When the code is one of two hundred seventy cycles per minute, the oscillator N is operated to actuate its contact members 62 and 7 5. With the contact member 62 actuated, the slow releasing relay R is energized to effect the energization of the brake valves D and D to thereby reproduce an emergency condition of the brakes. When oscillator N is actuated onehundred eighty times per minute, its contact member 74 alternately connects the generator G1 and the input circuit to the inductors 4i and 45 thereby keeping the auxiliary apparatus in step with the loco motive apparatus under the lap condition of the brake valve on the locomotive. Likewise when N is actuated, its contact member 7 5 alternately connects G1 and the input filter to the inductors and the auxiliary apparatus is synchronized with the locomotive apparatus. Thus we see that whichever one of the oscillators in the caboose is rendered active depending upon the position of the 3 engineers valve, the corresponding brake valves of the auxiliary mechanism are made to reproduce the brake function set up on the locomotive and the two oscillators synchronized to alternately receive and send the control and indication impulses. Furthermore, it is noted that the sending of the indication code at the caboose is completed only in the event the brake valves are in the proper positions.

Referring again to Fig. 1, the relay 76 is operated by the code impulses of carrier current picked up by the inductors 9 and 10. l/Vith relay 76 operated on code so as to supply current to the two halves of the primary 7 77 of a transformer 78 from the battery 79, an electromotive force is induced in the secondary 80 which is rectified by the full wave rectifier 81 to energize a slow releasing relay V 82. As long as relay 82 is energized, a circuit is completed to the indicator 83'wl1ich may be a lamp, a bell or a magnet. It follows that as long as any of the codes, eighty, one hundred twenty, one hundred eighty or two hundred seventy are received on the I locomotive, the relay 82 is energized and the indicator 83 rendered active. This indicator therefore informs the engineman that the proper brake condition is produced in the ca- A boose.

Let us now consider the operation of the system as a whole, assuming first that the engineers brake valve is in the running position. WVith the handle 3 placed in the running position, the oscillator M is rendered active andas it oscillates at ,a frequency of one hundred twenty times per minute, the generator G supplies an impulse of carrier current to the rails 1 and 1 one half of each cycle, and during the other half of each cycle 1 ion the apparatus on the locomotive is placed in condition to receive an incoming impulse. These impulses supplied to the rails by the generator G are picked up by the inductors at the caboose and first applied to the input circuit of the reciving apparatus, through a back contact of the armature 68 of the service magnet D After a few cycles, the oscillator N tuned to one hundred twenty cycles per minute is rendered active and the valves D and D become energized in series. As the oscillator N continues to oscillate in step with the incoming impulses, its contact 57 alternately connects the input and output circuits of the auxiliary mechanism to the inductors at the caboose so arranged that the input circuit is connected during the period that the output circuit at the locomotlve is completed and the output circuit at the caboose completed during the period the input circuit on the locomotive is closed. During the period the output-circuit on the caboose is completed, an impulse of carrier current is supplied to the rails in the event the brake valves are in the proper condition. These impulses supplied by the caboose apparatus to the traffic rails are picked up by the m ductors at the locomotive to operate the relay 76 and in turn produce the indication at 83. In a similar manner the system operates for each of the brake conditions release, lap and emergency. Whenever the engineers valve B is placed at service position, no oscillator on the locomotive is active and no code supplied by the locomotive equipment. The failure to receive a code at the caboose results in all the brake magnets being deenergized and the auxiliary mechanism effecting a service application of the train brakes. In the event a local failure of the auxiliary mechanism occurs, the service valve D becomes deenergized to set up a service application and as valve D becomes deenergized its armature 68 breaks contact with its front contact to open the output circuit of the generator G1. The failure to receive a return indication on the locomotive results in the indicator 83 being extinguished to inform the engineman that the auxiliary brake apparatus in the caboose is in the service application condition.

Such a system as here disclosed is comparatively simple in construction. It contains only one continuously moving member at each end of the train which carries out the function of shifting the apparatus from the receiving to the sending condition and which energizes the operating circuit selected. A change from one operating condition to another can be established in a comparatively short time as the oscillators readily respond to their respective code frequency. The display of but a single indication on the locomotive for all conditions of the auxiliary brake apparatus in the caboose permits of a simple indicating device.

lVhile my invention is here disclosed as a control system for the brakes of a railway train whereby the functions of the usual engineers valve of the locomotive are reproduced by an auxiliary brake controlling mechanism in the caboose, it is to be understood that the auxiliary brake controlling apparatus can be readily controlled independent of the engineers valve by having the contact 2 of Fig. 1 operated independent of the brake valve handle 3. As a matter of fact, numerous ways may be employed to select the active oscillator and to establish the different brake controlling conditions. Furthermore, it is to be understood that my invention is adapted to other control systems where mechanisms having one or more operating conditions are to be controlled from a remote pointand an indication is to be returned from the mechanism to the control point.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A control system comprising a mechanically tuned oscillator, a sending and a receiving circuit associated with said oscillator, means controlled by said oscillator to alternately close the sending and receiving circuits once each cycle of oscillation, a second mechanically tuned oscillator located at a second point, a sending and a receiving circuit associated with the second mentioned oscillator, means controlled by the second oscillator to alternately close its associated sending and receiving circuits once each cycle of oscillation, means for influencing the receiving circuits of one oscillator by the current supplied by the sending circuit of the other, an operating mechanism controlled by each receiving circuit, and synchronizing means for causing the receiving circuit of one oscillator to be closed when the sending circuit of the other is closed.

2. A control system comprising, a control location and a receiving location spaced apart, an operating mechanism having a plurality of operating functions located at said receiving location, a mechanically tuned oscillator for each operating function of said mechanism at each of said locations with the two oscillators corresponding to a. given function having the same distinctive period of oscillation, means at the control location for selectively rendering active any one ofthe oscillators at that location, transmitting and receiving means controlled by the active os- CPI cillator to render active the corresponding oscillator at the receiving location for causing the operating mechanism to effect the corresponding function, and an indicating device at said control location controlled jointly by the operating mechanism and the active oscillator at said receiving location.

3. A control system comprising, a source of carrier current, a sending circuit, a plurality of mechanically tuned oscillators each having a distinctive period of oscillation and each adapted to connect the source to the sending circuit once each cycle of its oscillation, means to selectively render any one of said oscillators active and thereby establish different codes of the carrier current supplied to the sending circuit, a plurality of operating devices, and a receiving and decoding means influenced by said sending circuit selectively responsive to the different codes to selectively control said operating devices.

4;. Apparatus for the control of train brakes including, a brake controlling mechanism adapted to produce the release, running and brake applying conditions of the brake pipe pressure of a train, a mechanically tuned oscillator for each of said conditions with each having a distinctive period of oscillation and each adapted when active to establish the corresponding condition of the brake controlling mechanism, a receiving circuit to control said oscillators, means to supply said receiving circuit with a current at codes corresponding to the difierent periods of oscillation of the oscillators to select- Which oscillators shall be active, and means to select the code to be supplied and thereby determine the condition of the brake pipe presssure.

5. Apparatus for the control of train brakes including, a brake controlling mechanism adapted to produce the release, running, and brake applying conditions of the brake pipe pressure of a train, a vibrating member for each of said conditions with each member having a distinctive period of oscillation and each adapted when active to es tablish the corresponding condition of the brake controlling mechanism, an elecfroresponsive means associated with each of said members, a receiving circuit to control said electroresponsive means, means to supply said receiving circuit with current at codes corresponding to the different periods of oscillation of the said members to select Which member shall become active, and means to.

with a different coded current for each of said conditions, a main relay controlled by the receiving circuit operated at a frequency corresponding to the code supplied, a plurality of secondary relays selectively responsive to the frequency of operation of said main relay, and circuits selectively controlled by said secondary relays for controlling the brake controlling mechanism.

. 7. Apparatus for the control of train brakes including, a brake controlling mech anism capable of producing the release, run ning, lap, service and emergency conditions of the brake pipe pressure of a train, a receiving circuit, means to supply said receiving circuit with a different coded current for each of said conditions, a main relay controlled by said receiving circuit operated at a frequency depending upon the code supplied, a plurality of secondary relays selec tively responsive to the frequency of operation of said main relay, and circuits selectively controlled by said secondary relays for controlling the brake controlling mechanism.

8. Apparatus for the control of train brakes including, a brake controlling mechanism capable of producing the release, running, lap, service and emergency conditions of the brake pipe pressure of a train, a receiving circuit associated with said mechanism, means located at another point on the train to supply said receiving circuit with a different coded current for each of said conditions, a main relay controlled by said receiving circuit operated at a frequency depending upon the code supplied, a plurality of mechanically tuned relays selectively responsive to the frequency of operation of said main relay, and circuits selectively controlled by said mechanically tuned relays for controlling the brake controlling mechanism.

9. Apparatus .for the control of train brakes comprising in combination with the usual engineers brake valve on the locomotive, an auxiliary brake controlling mechanism located at another point on the train adapted to reproduce the usual operating functions of the engineers valve, means controlled by the position of the engineers valve to supply a different coded current for each operating function, a transmitting and receiving means influenced by said coded current, a main relay controlled by said transmitting and receiving means operated at a frequency depending upon the code supplied, and a plurality of mechanically tuned devices selectively responsive to the frequency of operation of the main relay for causing the auxiliary brake controlling mechanism to register with the position of the engineers brake valve.

10. Apparatus for the control of train brakes comprising in combination with the usual engineers brake valve on the locomotive, an auxiliary brake controlling mechanism located at another point on the train adapted to reproduce the usual operating functions of the engineers valve, a mechanically tuned oscillator for each position of the engineers valve with each oscillator having a different period of oscillation, means controlled by said oscillators to supply a current coded at the frequency of the period of oscillations of the oscillator corresponding 'to the position of the engineers valve, a

' transmitting and receiving means influenced by said coded current, a plurality of mechanically tuned devices controlled by the transmltting and recelving means selectively responsive to the frequency of the code supplied for causing the auxiliary brake controlling mechanism to register with the position of the engineers brake valve.

11. Apparatus for the control of train brakes comprising in combination with the usual engineers valve on the locomotive, a mechanically tuned oscillator for each of the several operating conditions of the engineers valve with each oscillator having a distinctive period of oscillation, means torender active the oscillator corresponding to the condition of the engineers valve, an auxiliary brake controlling mechanism located at another point on the train capable of reproducing the brake conditions of the engineers valve, a mechanically tuned oscillator for each of the brake conditions of the auxiliary mechanism and arranged that each oscillator has the same period of oscillation as that of the oscillator associated with the corresponding brake condition of the engineers valve, and transmitting and receiving means controlled by the active oscillator associated with the engineers valve to render active the corresponding oscillator associated with the auxiliary mechanism for causing said auxiliary mechanism to register with the condition of the engineers valve.

12. Apparatus for the control of train brakes comprising in combination with the usual engineers brake valve on the locomotive; two sets of mechanically tuned oscilla tors located apart and with each set having an oscillator for each of the several operating positions of the brake valve, and arranged that each oscillator of a set has a distinctive period of oscillation, but which is the same as that of the corresponding oscillator of the other set, means controlled by the position of the engineers brake valve to render active the corresponding oscillator of one set, a transmitting and receiving means controlled by the active oscillator to render active the oscillator of the second set having a like period of oscillation, an auxiliary brake controlling mechanism on the train capable of reproducing the operating conditions of the engineers valve, and means controlled by the second mentioned active oscillator for causing the auxiliary mechanism to register with the engineers brake valve.

13. A control system including, a control station, a remote station, an operating mechanism at the remote station having a plurality of operating conditions, means at the control station to supply a coded current with a different code for each operating condition of the operating mechanism, means to select the code to be supplied, a first transmitting and receiving means influenced by said coded current, means at the remote station controlled by said transmitting and receiving means selectively responsive to the dillerent codes for causing the operating mechanism to establish the corresponding operating condi tion, means controlled by the operating mechanism to supply a coded current with a different code for each operating condition, a second transmitting and receiving means influenced by the coded current supplied at the remote station, and an indicating device at said control station alike responsive to all the coded currents supplied by the means at the remote station.

14. A control system including a control station, a remote station, an operating mechanism at the remote station having a plurality of operating conditions, a transmitting and receiving means under the control of an operator at the control station for causing the operating mechanism to establish any desired operating condition, and an indicating device at the control station under the joint control of the operating mechanism and the said transmitting and receiving means to display the same indication for all operating conditions of said mechanism and energized when and only when the operating mechanism registers with the condition selected by the operator at the control station.

15. Apparatus for the control of train brakes comprising in combination with the usual engineers brake valve on the locomotive, an auxiliary brake controlling mechanism located at another point on the train adapted to reproduce the usual operating functions or" the engineers valve, means controlled by the engineer for causing the auxiliary brake controlling mechanism to register with the position of the engineers valve, an indicating device on the locomotive, and means for causing said indicating device to display the same indication for all operating conditions of the auxiliary mechanism When and only when said auxiliary mechanism registers with the engineers brake valve.

In testimony whereof I aifix my signature.

ANDRElV J. SORENSEN. 

